Refrigerating apparatus



T. W. KOERNER REFRIGERATIN'G APPARATUS 'Feb.- 22, 1938.-

Filed July 2, 1935 -1NvENToR- Tampa/Ez M (afg/wp I BY y - ATTGRNEY 55 U shaped cross-sectional form,

Patented Feb. 22,' 1931sY UNITED sTATEsj nEFmeEnA'rING APPARATUS y i Theodore W.'Koerner,

- by mesne assignmen Corporation, Detroit, Mich.,

` Maryland.

Application July 2, lass,

1` claim. (c1. lcfa- 126) My invention pertains to refrigerating apparatus of the expansion type and more particularly to an improved refrigerant evaporator and method of making the same. Y

It is an object of my invention to provide a refrigerant evaporator construction which is o'f smooth regular'conformation having spaced innerland outer walls the edges of one of the walls v`being, turned to `provide a smooth rolled pe,-

riphery and abutting 'the edges of the other wall.. towhich it is welded to define a substantially smooth `at surface whereby the evaporator may ,be covered uniformly with a' protective coating of a substance such as a vitreous enamel.

It is also an object of my invention AVto proA vide a refrigerant evaporator which may be readily constructed from flat sheet metal blanks 4united to provide inner and outer walls having their'edges turned together to dene' a smooth dat sur/face and a, smooth rolled upper periphery. A

It is a further object of my invention to provide I an improved refrigerant evaporator and method ofniaking vthe same 'of spaced inner and outer walls of sheet metal which comprises folding-the edge of either the inner or the outer sheet to provide ,a smooth rolled periphery, terminating the inturned edgethereof abutting the edge of the .other sheet and welding the abutting edges together to define a substantially fiat smooth surlface. f

The invention itself, however, both as to its organization and its method'of operation, togetherwith additional objects and advantages thereof, will best be understood vfrom the follow-v ing descriptionv of a specific embodiment, when read in conjunction with the accompanying V drawing, inwhich: Y

Fig. l is a side elevational view ,partly broken s away and sectioned showing a refrigerant evapo- -rator constructed vin accordance'with my invention;

Figs. 3 and 4 are detail 'sectional views on lines III-IIL and IV'IV thereof;

Fig. -5 is an elevational view showing a blank sheet .of metal whichA may' be folded to provideside walls of the evaporator; and

Fig. 6 is a side elevational view illustrating a.A stage in the construction of anevapora'tor after a coifrugated sheet has been united with the blank sheet, the edges of, which have 4been foldedover. before thel unitedl bent into 'isfa cross-,sectional view on line rrr-11'A structure has been portions 9 between Youter wall directly'engage the -inner wall 5 to endspf the v ent I5 are I4 in the manifolds I3 in any suitable manner, as

corrugations 1'to' upper edges' of ripheries I1.\ The Detroit, 4'Mich., assignor, ts, to Nash-Kelvinator a `corporation of serial No. 29,536

Referring more specifically to Figs. 1 vand 2T of the drawing I have shown a cooling unit I constructed inaccordance with my invention for absorbing heat by the vaporization of a volatile refrigerant therein. Such an evaporator con- 5,

sists of an 'outer sidewall 3, the ,outer edges of which are bent upwardly to provide a U shaped cross sectional conformation, lenclosing and spaced from an inner wall 5 which is likewiseof 'U shaped conformation.

In order that the walls 3 and 5 may be rigidly secured in spaced relation to provide space for the vaporzation' of a volatile liquid refrigerant therebetween, a plurality of parallel spaced cor- Arugations 1 are provided-in the metal sheet 3 16 forming the outer'` walls of `the Ievaporator. The

.the corrugations 1, in the which they are spot welded at intervals although a hermeticallysealed engagement therebetween is neither necessary nor desirable. As shown, thef refrigerant receiving corrugations'1 in the outer wall 3 extend vertically down the sides of the evaporator and pass \under the bottomthereof where they connect a large feeder corrugation I I which extends longitudinally along the center of the bottom wall for supplying liquid refrigerant to the smaller corrugations 1 branching therev from. The inner wall 5 of the evaporator is provided with large horizontally disposed corrugations I3 near the upper edges thereof which com- .prise refrigerant manifolds for drawing the refrigerant vapor from the upper ends of the vertical corrugations1 along the sides. For this purpose a tubular vent I5 extends transversely across the upper portion of the evaporator having its opposite ends operatively connected to the refrigerant manifolds I3 in the inner walls of the evaporator, as shown in Figs. 2 and 3. The

hermetically sealed into 40 suitable apertures provided in, flattened portions by welding for example. Smaller horizontal corrugations I6 at a lower level in the inner walls 5 serve tcsupport shelves or partition members in the evaporator and also interconnect the vertical circulate the refrigerant.I 'Ihe the inner and outer walls of the evaporator are united byfolding'overvv 'the edges of either the" inner ortheouter sheet to form a ,smooth rolled peripheryf. around the l the evaporator. 'The edges of the lower`walls and the vertically extending edges are 'similarly united toprovide-smooth rolled 1:e'

uppermost edges of edges abut the extended 5 folded outwardly and extend back along the in)ner surface of the wall I to abut the edges of the outer wall I. The abutting edgesdeilning a substantially ilat smooth surface are Iconveniently seam welded together close to the abutting' edges as by means of seam welding rolls, or in any suitable manner, as will be readily understood by those skilled in theart. The vent tube A'Il interconnecting theI manifolds -I3 is provided with an a'perture extending through the upper 'wall thereof for connection with the suction line il of a refrigerating system. 'I'he aperture comprises a down pressed ange portion 2| for supporting a Ysuitable connection fitting 2l which maybe threadably engaged therein for operatively connecting the` suction line conduit il thereto.'y v'I'he Y volatile liquid refrigerant is supplied to the evap-N orator I through an inlet tting 2B located centrally *between the edges of the lower walls of the evaporator in the open end of the large feeder corrugationll as shown in Figs.- 1 and 4. An annular ring 21 is secured between oppositely diverging portions of the bottom walls 3 and 5 of the evaporator where it may be secured in any suitablemanner, as by welding or soldering. An`aperture passing through the ring 21 is threaded to receive the inlet iltting 2l which is threaded therein and serves to operatively connect a refrigerant line 29 extending fromH-the refrigerant condenser or other source of refrigerant to the evaporator. Inconstructingmyrefrigerantevaporator a first blank sheet 3| is provided having restricted corners 33, as shownln Fig. 5, and the outwardly projecting edges of the sheet are folded back along welded at intervals to the adjacent dotted lines l5. When the edges of the blank are turned back to a position corresponding to the innermost dottedillne l1, the

- smooth rolled edges I1 are provided around the periphery of the sheet and the inturned edges project inwardly substantially along -the innermost dotted line 81 being flattened against the sheet. A second sheet. comprising they outer wall I of the evaporator, is placed upon the blank sheet with its outwardly projecting edges abutting the inturned edges of the blank thus deilning a substantially smooth flat surface therewith. The abutting edges are then seam welded together as by passing them between seam welding rollers 4I, as shown in Fig. 3, or in any suitable manner as will be readily understood'by those skilled in the art. As will be understood`the two sheets Il and 39 are provided with suitable refrigerant circulating corrugations such as 1,13, and Il before theyareunited. u

'I'he mutually engaging surfaces between the corrugations 'I of the outer wall are disposed inf intimate engaged relation against the surfaces of the inner wall and the engaging portions are spot provide a rigidly united structure, Vas shown in Fig.r 6.l After the inlet 43,109,199 l l y connection 25 has been securedy between the spaced' edges of the sheets, as previously set forth, the fabricated structure is then distorted into the substantially U shaped cross sectional conformation, as shownl in Fig. 2. 'I'he refrigerant vent tube I5 is then inserted between the refrigerant manifolds i3 which have apertures into which it is hermetically sealed as by welding orv soldering aspreviously set forth. It will be understood that the method of construction is similarwhether theedges of the inner.wall of the evaporator are y turned outwardly to make the smooth rolled pe-v riphery I1 integral with the inner wall as shown, or the .edgesof-'fthe louter wali. are turned 'inwardly to ,make roll Il integral with the outer wall. By providing rounded corners on the blank sheet there areno welded joints at .the corners when it is bent yto-form the nished evaporator.

In myconstruction the disxaidvantagesV of previous evaporators presenting sharp cornersamd edges is entirely eliminated, and the completed structure may be provided with la uniform coating of enamel such as porcelain which will be of uniform thickness overall to protect it from corrosion andl present a sanitaryA pleasing appearance, and it is ready for mounting within a compartment to be refrigerated thereby.

It will be seen that I'have provided an improved vevaporator and method of constructing the same whereby the sharp edges of the blank sheets are conveniently turned and welded together in abutting relation and only smooth fiat and rolled surfaces are exposed on which a vitreous enamel may be coated uniformly throughout. y

Aside from the specific embodiment of the invention herein shown and described, it will be understood that numerous details of the construction may be altered or omitted-without departing from the spirit and scope of the invention as disy closed andI claimed, and that I do not desire to limit the invention to the exact constructions herein set forth.

I claim as my invention: o A sheet 'metal refrigerant evaporating element comprising sheet metal material formed to provide inner and outer walls spaced apart for the passage of refrigerant and an inlet opening, one

lof said walls including material integrally united therewith and having a reversely bent portion forming a rolled beadv extending continuously,

except for said inlet opening, around the periphery oi' the said one wall including the four corners thereof, the extreme edge of said reversely bent portion -being in uniformly continuous abutting' engagement with the peripheral edge of the material forming the other wall and said. extreme and peripheral' edges being locatedlat suilicient distance from said rolled bead to permit vseam welding between the material forming one wall andthe return bend of said material and also to permit seam welding between the two walls with the same operation of seam welding. t

THEODORE W. KOERNER. 

